Verticinone, an isosteroidal
alkaloid separated from Bulbus Fritillaria (Chinese name "Bei-mu"), was evaluated for its
analgesic activities in murine models of inflammatory and
neuropathic pain. It was shown that oral administarion of
verticinone could significantly inhibit
acetic acid-induced writhing response in a dose-dependent way, and the writhing inhibition of 3 mg/kg
verticinone was 66.2%, which was approximately higher than that of 200 mg/kg
aspirin. In the
formalin test, a high dose of (3 mg/kg)
verticinone could inhibit the nociceptive response of both phases, but the lower dose (1.5 mg/kg) could only inhibit the second phase response, which suggested that
verticinone might exert its
analgesic effect through both central and peripheral mechanisms. In addition, in
formalin and
acetic acid tests, the spontaneous locomotive activities of the mice treated with
verticinone were transiently greatly decreased when compared with the vehicle group. In the rat model of
paclitaxel induced
neuropathic pain, in contrast to the declined
analgesic effect of
morphine after repeated administration with the same dose, a relatively constant
analgesic effect of
verticinone was observed. These investigations suggested that
verticinone could exert a good antinociceptive effect on inflammatory
pain and
cancer-related
neuropathic pain probably through both peripheral and central mechanisms, and it might be partly involved with some sedation effects.
Verticinone is expected to become a potentially novel
sedative-
analgesic agent without producing tolerance and dependence, but further studies are still urgently needed to elucidate the precise mechanisms and activities of it.